Desulfurization process and novel bimetallic sorbent systems for same

Abstract

Novel sorbent systems for the desulfurization of cracked-gasoline and diesel fuels are provided which are comprised of a bimetallic promotor on a particulate support such as that formed of zinc oxide and an inorganic or organic carrier. Such bimetallic promotors are formed of at least two metals of the group consisting of nickel, cobalt, iron, manganese, copper, zinc, molybdenum, tungsten, silver, tin, antimony and vanadium with the valence of same being reduced, preferably to zero. Processes for the production of such sorbents are provided wherein the sorbent is prepared from impregnated particulate supports or admixed to the support composite prior to particulation, drying, and calcination. Further disclosed is the use of such novel sorbents in the desulfurization of cracked-gasoline and diesel fuels whereby there is achieved not only removal of sulfur but also an increase in the olefin retention in the desulfurized product. Such sorbents can also be utilized for the treatment of other sulfur-containing streams such as diesel fuels.

Description

[0001]This application is a continuation-in-part of U.S. patent application Ser. No. 09 / 864,907, filed May 24, 2001, now U.S. Pat. No. 6,531,053 which was a divisional of U.S. patent application Ser. No. 09 / 460,067, filed Dec. 14, 1999, now U.S. Pat. No. 6,274,533.[0002]This invention relates to the removal of sulfur from fluid streams of cracked-gasolines. In another aspect this invention relates to sorbent compositions suitable for use in the desulfurization of fluid streams of cracked-gasolines and diesel fuels. A further aspect of this invention relates to a process for the production of sulfur sorbents for use in the removal of sulfur bodies from fluid streams of cracked gasolines and diesel fuels.BACKGROUND OF THE INVENTION[0003]The need for cleaner burning fuels has resulted in a continuing world wide effort to reduce sulfur levels in gasoline and diesel fuels. The reducing of gasoline and diesel sulfur is considered to be a means for improving air quality because of the nega...

AI Technical Summary

Problems solved by technology

The presence of oxides of sulfur in automotive engine exhaust inhibits and may irreversibly poison noble metal catalysts in the converter.

Such adverse effect on olefin content is generally due to the severe conditions normally employed to remove thiophenic compounds such as, for example, thiophenes and alkyl dibenzothiophenes, which are some of the most difficult sulfur-containing compounds to be removed from cracked-gasolines.

In addition, there is a need to avoid a system wherein the conditions are such that the aromatic content of the cracked-gasoline is also lost through saturation.

In removing sulfur from diesel fuels by hydrodesulfurization, the cetane is improved but there is a large cost in hydrogen consumption.